Freddy Dumortier is full professor at Hasselt University (Belgium), he is a member of the Royal Flemish Academy of Belgium for Sciences and the Arts, and he was president of the Belgian Mathematical Society. He was a long term visitor at different important universities and research institutes. He is the author of many papers and was the organizer of different international conferences among which Equadiff 2003 in Hasselt. His main results deal with singularities and their unfolding, singular perturbations, Lienard equations and Hilbert's 16th problem. Jaume Llibre is full professor at the Aut...